Galaxies are Forever – Part One

The Sculptor Galaxy

Galaxies don’t have any dark matter, they are amazing and they are eternal.

Galaxies are truly amazing. We see lots of pictures of them with colour enhancement and they beautiful entrancing pictures. In New Zealand, Aotearoa, on the plains of Mt. Taranaki at the southwest side of the North Island, the Royal Astronomical Society of New Zealand, (Raisins for short), gather on clear moonless nights. There are two groups. One group sets up and mans about 10 telescopes on a flat cow paddock, while the other sits inside a camper trailer in total darkness. Total darkness means just that. Windows and doors are sealed from light. There are no cell phones and no watches to give off light. Absolute total darkness; black and usually silent. This group is the observing group; their eyes are adjusting to total blackness. This takes a little over 20 minutes. There is a knock on the door of the camper asking if the observers are ready. If the observers have seen no light in the duration of their isolation, the door opens and the observers exit the camper into the night guided by their outside companions. The observers have to be guided since they have their eyes closed.

The observers are led to different telescopes where they are told they can open their eyes and have a look through the telescope before them which is trained on a distant galaxy. The observer opens their eyes and bends over to the eyepiece to see a spectacular vision of some spiral galaxy or, perhaps, a pair of galaxies. Even though night vision is black and white, no colour in night vision, the stars of the galaxy can be made out as bright shining dust revealing the shape of the observed galaxy.

When the observer is finished gazing at this particular galaxy, they again close their eyes and stand up to be led by their guide to another telescope and and another galaxy. And another spectacular vision of these amazing objects.

The two groups continue for about an hour or so until the temptation to look at the night sky is too great for anyone. The Southern Hemisphere night sky, complete with Magellanic Clouds and Display of the centre of the Milky Way, is breathtaking. The Pacific Ocean stretches to the west and is beautifully lit by billions of stars. Mt Taranaki is majestic, rivalling Mt. Fuji, reaching into the night sky. Slowly some night vision gives way to the colours of the stars. No photograph can compare.

Galaxies were once called “island universes”. They are extremely large: about 300 thousand light years across. Also, galaxies seem to all have almost the same mass, in the order of a hundred billion solar masses. And they all, with the exception of only two galaxies that we know about, have a remarkable property that has confounded the greatest minds of astrophysics. That is that all the stars in the galaxy, except for those very close to the centre, are measured to orbit the galaxy with the same orbital velocity. This has exposed how astronomers really don’t understand gravity.

Let us go through this without resorting to the occult, magic faerie dust, or the noodly arms of the Flying Spaghetti Monster. Let us look at a typical galaxy that has a very clear and definite flat velocity rotation profile, like NGC 3198, in the constellation of Ursa Major in the Northern Hemisphere, near the bear’s hind foot. It has a very definite and pronounced flat velocity profile and distinct spiral morphology. That means it looks like a spiral. OK, so how the hell can a galaxy look like a spiral when all its stars are going around it at the same speed? Shouldn’t the outer stars be moving faster in order to keep the spiral shape? Forget all this nonsense about Kepler. How can this galaxy and many others be spirals? This doesn’t make any sense.

As a result of this question, we see a plethora of complete nonsense from every corner trying to explain or answer the question: How can galaxies be spirals if all their stars have the same orbital velocity? And it gets piled higher and deeper every day. The flat velocity rotation profile is the very essence of claims of the existence of dark matter and yet, even if dark matter existed, which it doesn’t, it would not explain the spiral shape of NGC3198, or the Andromeda Galaxy or thousands and thousands of other spiral galaxies. All of these bizarre explanations using dark matter or some modification of Newton’s theory of gravity, are completely absurd.

There are two things at this point: a spiral and the orbital speed. A spiral is a non-symmetric shape. One side is not a mirror image of the other; it is inverted. One reason this is important is that a spiral shape cannot be fed into the mathematical models that are used to study this question. The shape of the input has to be symmetric, which it isn’t, in order to be fed into a professional astronomer’s mathematical model or else the model will collapse. Suffice it to say that if galaxies are spirals, and about 40% of galaxies are spiral galaxies, 20% are barred spirals and the rest are elliptical, then the stars must have circular orbits. If they didn’t have circular orbits the galaxy wouldn’t be a spiral for very long. Also, the only way a galaxy can maintain a spiral shape is if its member stars are in circular orbits which makes the galaxy itself rotate as a rigid body. That is conclusive. There is no getting around it.

However, there exists a model of spiral galaxies in which stars “jump” spontaneously from one spiral arm to another and just hang around that spiral arm for a while before jumping off again to the next spiral arm, but this is ludicrous. Also, it would show up in the velocity profile which it doesn’t.

So much for this spiral shape. What about the flat velocity rotation profile? What’s up with that? Well, first let’s find out how we measure this orbital velocity. Even though a galaxy may be “rotating” quickly, it is very large and there is no way we have observed it for long enough to “see” the galaxy actually move or physically rotate. So obviously watching a galaxy rotate and timing it with a stopwatch is out of the question. A rough guess is that it takes hundreds of millions of years for a galaxy to rotate. We’ve only been watching them since about 1922. So how do you measure how fast a galaxy is rotating?

I would now like to talk about the work of D. S. Mathewson at the Silver Springs Observatory on the edge of the Warrumbungle National Park near Coonabarabran, NSW, Australia, the same observatory that pictured the supernova in 1987 in conjunction with a neutrino burst detected by SNOLAB in Sudbury, Canada. Mathewson worked with a 10” telescope. At the focal point in the eyepiece holder, he inserted a slit on a circular disk that could be rotated by hand and aligned with the major axis of any galaxy he was observing. The plane of a spiral galaxy is inclined to our line of sight and appears as a spiral with a major and minor axis. The major axis is the longest part of the galaxy from end to end. The telescope was aimed with the galaxy dead centre in the field of view. The image of the this slit along the length of the galaxy was passed through a prism to make a rainbow, a spectrum. The spectrum would be in the form of lines (spectral lines) which are far enough apart in order to isolate just one of them. Mathewson chose a spectral line of Hydrogen since there’s lots of Hydrogen in stars and the line is fairly bright. However, the spectral line, which is an image of the slit, was not straight. It took the shape of the velocity profile of the galaxy because the galaxy is rotating and, you know, Doppler effect. Canadians know a lot about Doppler effect. The spectral line was recorded using a photoelectric cell and stored on a magnetic tape using a computer.

He measured the rotation profiles of over 1200 galaxies and all of the rotation profiles were flat, as I mentioned before. He was astounded. So was everyone else. The bottom line is that the rotation velocity, or speed of orbit of stars in a galaxy, is measured by the shifting of spectral lines and not by watching a galaxy rotate and timing that rotation. And that opens a door for us to look through and figure things out for ourselves.

We note that the spiral shape of a galaxy is ignored by most astronomers when trying to figure out its make up. So the question we mere mortals ask is: How can a galaxy have a flat velocity rotation profile and be a spiral at the same time? Please note that the question is not: How can the stars all have the same orbital speed and be a spiral at the same time? That is because the stars of a galaxy cannot all have the same orbital speed and the galaxy have a stable spiral shape.

Note, as mentioned before, 40% of galaxies are spirals, 20% are barred spirals and the rest are ellipticals. That’s way too many spiral galaxies for their spiral shape to be either by chance or transitory. We must conclude that their shape must be a stable, long lasting, shape. They retain their spiral shape for a very, very long time.

So, next time you see a spiral galaxy, ask yourself: How come it’s a spiral? Is it from the actual rotation of the galaxy itself?